Filter
Top Products
Hitachi Command Control Interface (CCI) User and Reference Guide 173
4.3 Splitting and Deleting Pairs (Pairsplit)
The pairsplit command stops updates to the secondary volume of a pair and can either
maintain (status = PSUS) or delete (status = SMPL) the pairing status of the volumes (see
Table 4.3). The pairsplit command can be applied t
o a paired logical volume or a group of
paired volumes. The pairsplit command allows read access or read/write access to the
secondary volume, depending on the selected options. When the pairsplit command is
specified, acceptance of write requests to the primary volume depends on the fence level of
the pair (data, status, never, or async). Table 4.5 lists and describes the pairsplit command
parameter
s and returned values. Table 4.6 lists and describes the error codes for the
pair
split command.
Pair
splitting
command
Server A
Server B
Primary
volume
(Secondary
volume)
Secondary
volume
(Primary
volume)
Paired logical volume
Figure 4.2 Pair Splitting
The primary volume’s server is automatically detected by the pairsplit command, so the
server does not need to be specified in the pairsplit command parameters. If the -S option
(simplex) is used, the volume pair is deleted, the volumes are returned to the simplex state,
and the primary and secondary volume status is lost. Paired volumes are split as soon as the
pairsplit command is issued. If you want to synchronize the volumes, the pairsplit command
must be issued after write I/Os to the paired volume have completed (see section 4.3.1 for
examples).
Note:
You can create and split ShadowImage pairs simultaneously using the -split option of
the paircreate command (refer to section 4.2).
Note on Quic
k Split: If “$HORCC_SPLT=QUICK” environment variable is set (USP V/VM or
USP/NSC), the “pairsplit” and “paircreate -split” operations will be performed as Quick Split
regardless of the system option mode 122 setting on the SVP. The $HORCC_SPLT
environment variable is ignored by 9900V/9900.